1. Field of the Invention
The invention relates to automatic dishwashing detergent compositions. In particular, the invention relates to low temperature dishwashing detergent compositions.
2. Background
The current trend in automatic dishwashing is to improve the environmental impact of the cleaning process. This has manifested itself mainly in three ways, firstly by the use of less water during the cleaning cycle, secondly by the reduction of the use of phosphates in the detergent compositions and thirdly by the reduction in energy consumption of the machines during the cleaning cycle.
The latter trend has lead to new machines that are increasingly offering wash programs using lower cleaning and drying temperature settings than have historically been on offer. Where previously, ten years ago, an economy wash may have been carried out at 55° C., now there are commercially available dishwashing machines that offer programs at temperatures as low 45° C. and even 40° C.
This drop in wash temperature raises a number of different technical challenges to the manufacturers of detergent formulations to maintain cleaning performance at these lower temperatures.
One of the issues is the cleaning of fats from soiled tableware. Currently animal and vegetable fats are melting in machines and wash programs above 50° C. This makes them relatively simple to emulsify and remove from the surface of tableware.
However at lower temperatures, around 40-45° C., it becomes increasingly difficult to remove such fats as this temperature may be below their melting point. This is a particular problem with certain animal fats and hydrogenated plant fats, triglycerides and fatty acids.
This can lead to unpleasant fatty deposits being left either on the tableware or on the internal surfaces of the dishwasher itself at the end of cleaning cycles when current detergent formulations are used.
It is the object of the present invention to address this problem.